Rome, January 22 - A preliminary investigations judge in the Sicilian city of Caltanissetta issued an arrest warrant Friday against Cosa Nostra fugitive boss Matteo Messina Denaro for ordering the assassinations of crusading anti-Mafia magistrates Paolo Borsellino and Giovanni Falcone in 1992. Messina Denaro, now 53, has been on the run since 1993. He has not been seen in public in over 20 years. An informant in 2014 helped authorities update their facial composite of the Mafia boss. Cosa Nostra mobsters turned State's witnesses Francesco Geraci and Vincenzo Sinacori told investigators Messina Denaro took part in a September 1991 Mafia summit to plan Falcone's assassination. Jailed boss of bosses Toto' Riina was at that summit, according to the informants. Messina Denaro also allegedly took part in an armed commando that failed to kill Falcone in Rome in February 1992, and that he had planned the hit on Borsellino ever since the magistrate was still a prosecutor in the city of Marsala. The crime boss is in the world's top 10 wanted men, according to Interpol.